Air Pollution & Asthma Through the Generations

Mothers exposed to air pollution pass asthma susceptibility to their children.

Women who live in areas with bad air pollution are more likely to have children with asthma. Magdalena Gorska, MD, PhD, is investigating how prenatal exposure to air pollution might cause asthma. She has shown that compounds in diesel exhaust cross the placenta. Once across the placenta, they activate biological mechanisms that can make a child more susceptible to asthma. She has started to identify the cells, pathways and molecules involved. That knowledge could reveal molecular or cellular targets for medications to treat and even prevent asthma.

Children Predisposed to Asthma

A mother’s exposure to air pollution is associated with increased rates of asthma among her children. Magdalena Gorska, MD, PhD, is investigating the biology underlying that association. She has shown that females exposed to diesel exhaust, either before or during pregnancy, have offspring more susceptible to asthma.

Crossing the Placenta

Dr. Gorska is discovering the biological mechanisms that link a mother’s exposure to air pollution with asthma in her children. She found specific molecules in diesel exhaust, known as polycyclic aromatic hydrocarbons or PAHs, cross the placenta. The PAH molecules then bind to specific sensor proteins on fetal immune cells known as natural killer cells.

Natural Killer Cells Promote Asthma

The sensor proteins, known as AhRs, trigger a cascade of biochemical reactions inside the natural killer cells. That cascade causes the cells to release molecules that increase inflammation and airway resistance — hallmarks of asthma. Dr. Gorska’s experiments showed that when natural killer cells were removed, asthma did not develop.

How Long Does It Last?

Dr. Gorska is now seeking to fully understand the sequence of events that lead from exposure to diesel exhaust through AhR binding, to natural killer cell activation and eventual susceptibility to asthma. She is looking for other mechanisms that might transfer asthma susceptibility to offspring, including breast milk and epigenetic changes. She is also watching to see if the predisposition to asthma is passed on from offspring to subsequent generations.